Dr Jami Shepherd. 2019 – 2023 (extended due to COVID)

Dr Shepherd’s goal was to create new imaging techniques using both photoacoustic and ultrasound imaging. Her multi-track approach was a response to new medical physics findings, theory development and the development of new instrumentation. She is based at the University of Auckland where she was made a Senior Lecturer in Physics in 2025, with the Agnes Blackie fellowship contributing career-building connections, as well as science.

Ultrasound is one of the most regularly used imaging techniques and is sensitive to elastic properties in the tissue.  Photoacoustic imaging is comparatively new and uses pulses of light to generate sound inside the tissue. This technique can be used to create images with optical contrast reaching centimetre depths, as opposed to millimetre depths with purely optical imaging.

Photoacoustics is especially suited for imaging blood vessels, as the inherent contrast of blood is far higher than surrounding tissues.  Combining both photoacoustics and ultrasonics enables sensing of both elastic and optical properties, therefore probing both structure and function of tissues.

Dr Shepherd’s aim was to advance photoacoustic imaging from soft-tissue into bone, and develop new functional imaging capabilities by quantifying blood flow. Conventional methods assume the entire body is made of water, which breaks down inside of bone.  Her team developed a method of accurately imaging inside of bone structure using an ultrasound-guided photoacoustic imaging technique, paving the way for assessment of hemodynamic parameters in bone.  They further developed a technique called photoacoustic vector-flow, which quantifies the magnitude and direction of flow at every pixel in a photoacoustic image.  This is particularly valuable in slow-flow situations where conventional ultrasonic Doppler breaks down, and in complex vasculature where the assumption of a single direction of flow is inaccurate.  These developments attracted external funding to support the next stage of research, including a Marsden Fast Start grant.